Post on 08-Jun-2020
transcript
9/7/2018
1
Ch 8: Endocrine Physiology
Objectives 1. Review endocrine glands of body.
2. Understand how hypothalamus controls endocrine system & sympathetic epinephrine response.
3. Learn anterior pituitary hormones & their effects on glands of body.
4. Understand some endocrine disorders.
1
1. Endocrine Glands of the Body
2
Endocrine glands of body: Pituitary = master endocrine gland Pineal gland = located in diencephalon Adrenal glands = located above kidneys Thyroid = located on anterior trachea Parathyroid glands = located on posterior trachea Gonads = ovaries & testes Pancreas GI tract
**Most of these glands controlled by hypothalamus!
Endocrine System = system involving regulation of body functions through use secretory glands & chemical messengers (hormones)
9/7/2018
2
3
> Hypothalamus part of both nervous & endocrine systems
Controls endocrine system 3 ways: 1. Hypothalamic nuclei secrete neuro-hormones through posterior pituitary. Supraoptic nucleus secretes ______________________
Paraventricular nucleus secretes __________________ 2. Hypothalamus secretes _________________or ____________________________which controls anterior pituitary.
3. Hypothalamus controls autonomic sympathetic
secretion of ____________________ by the
_______________________________
Oxytocin ADH
AP
PP
2. Hypothalamus controls endocrine system!
4
AP PP
Hypothalamus Directs Anterior Pituitary Secretions
Know hypothalamic hormone (acronym) and what it causes anterior pituitary to secrete!
Hypothalamus secretes: 1. ________________________________________________
2. ________________________________________________
3. ________________________________________________
4. ________________________________________________
5. ________________________________________________
6. ________________________________________________
Re
leas
ing
ho
rmo
ne
s
(___
RH
)
Inh
ibit
ing
ho
rmo
ne
s
(___
IH)
9/7/2018
3
5
AP PP
Anterior Pituitary Secretions (in response to hypothalamus)
Anterior Pituitary Response: 1. ________________________________________________
2. ________________________________________________
3. ________________________________________________
4. ________________________________________________
5. ________________________________________________
6. ________________________________________________
6
AP PP
Hypothalamus Directs Anterior Pituitary Secretions
Know hypothalamic hormone (acronym) and what it causes anterior pituitary to secrete!
CRH
GnRH
PIH
GHIH
TRH
GHRH
ACTH
FSH & LH
TSH
GH
NOT IN BOOK!
9/7/2018
4
7
ACTH
TSH
GH
FSH
PRL
LH
NOT IN BOOK!
Endocrine hormone regulation is through negative feedback. If blood levels of a hormone are too low, hypothalamus & pituitary increase their stimulatory hormone secretions. If blood levels of a hormone are too high, hypothalamus & pituitary decrease their stimulatory hormone secretions.
8 Fig 8.6
Anterior Pituitary secretions & their effects on target organs or glands:
Effects: Effects:
Stimulates mammary glands to make milk (lactation)
Stimulates body tissues to grow!
Produce T3 & T4 to regulate metabolism
Produce - Sex steroids - Cortisol
- Mature eggs & sperm - Produce estrogen & testosterone
Prolactin
ACTH
TSH
GH FSH
LH
9/7/2018
5
See Online Syllabus for Practice Endocrine Blank Flow Chart! Click HERE for blank, and HERE for KEY
9
10
How hypothalamus & neg. feedback regulates anterior pituitary secretions:
QUES: If the hypothalamus “senses” GH in blood is too high what does it do? ________________ What happens to anterior pituitary secretions of GH? ________________ If GH in blood is too low, hypothalamus does what? ________________ What does pituitary then do? ________________ If hypothalamus “senses” high estrogen or testosterone in blood it ________________ What does pituitary then do? ________________ If hypothalamus “senses: low thyroid hormones in blood it ________________ What does pituitary then do? ________________
9/7/2018
6
Review • Hypothalamic controls endocrine system
– Nuclei secrete ADH & oxytocin
– 4 Releasing hormones (CRH, GnRH, TRH, GHRH)
– 2 Inhibiting hormones (PIH, GHIH)
– Controls adrenal medulla secretion of epinephrine
• Anterior pituitary secretions & their target organs
– ACTH, TSH, GH, FSH, LH, PRL
• Endocrine glands of body – Pituitary, adrenals, thyroid, parathyroids, gonads, pineal gland, pancreas, GI tract
11
Growth Hormone (GH) Disorders: Clinical App Pg 203 & ONLINE
1. Insufficient GH = insufficient body growth > Pituitary dwarfism 2. Excessive GH – excessive body growth > Gigantism – when onset in childhood > Acromegaly – when onset in adulthood
9/7/2018
7
ACTH stim. Adrenal Cortex to make:
13
Under sympathetic response - hypothalamus stim. Adrenal Medulla to make
Fig 8.9
1. Sex steroids Ex. - estrogen, testosterone, progesterone
2. Mineralcorticoids Ex. - Aldosterone
(tells kidney tubules to increase salt, & then water retention)
3. Glucocorticoids
Ex. - cortisol
- Epinephrine
Clinical App Pg 209 & ONLINE Exogenous glucocorticoids and negative feedback on adrenal cortex
Adrenal Cortex Disorders: A. Cushing’s Disease (“hypercortisolism”) – Excess Cortisol
Clinical View Pg 206 & ONLINE Causes: - Excess hypothalamic CRH or pituitary ACTH - Adrenal gland tumor Clinical Presentation: - Hyperglycemia = ________________________ - Hyperlipidema _________________________ - Hypervolemia = _________________________ (“moon face”) - Hypertension = _______________________
9/7/2018
8
Adrenal Cortex Disorders: B) Addison’s Disease – Insufficient Aldosterone & Cortisol
Bronzing of skin
Clinical View Pg 206 & ONLINE Causes: - ↓hypothalamic CRH or pituitary ACTH. - Adrenal cortex tumor or autoimmune disorder. Clinical Presentation: Na+ retention by kidneys, excess K+ retention
- Hyponatremia = ________________________
- Hyperkalemia = ________________________
- Hypovolemia = ________________________
- Hypotension = __________________________________
- Anorexia = usually loss of body water
- Hypoglycemia - too little cortisol
- Skin bronzing (overstimulation of melanocytes)
16
Adrenal Cortex Disorders: C) Conn’s syndrome (hyperaldosteronism) Causes: - usually adrenal cortex tumor Clinical Presentation: Na+ retention by kidneys, excess K+ excretion in urine
- Hypernatremia = ________________________
- Hypokalemia = ________________________
- Hypervolemia = ________________________
- Hypertension = ________________________
- weight gain = usually retaining body water
9/7/2018
9
Adrenal Medulla Disorders: Pheochromocytoma = excessive norepinephrine/epinephrine
Clinical App ONLINE Causes: - adrenal medulla tumor Clinical Presentation: “fight or flight” symptoms
- Tachycardia = - Hypertension = - Hyperventilation = - Hyperglycemia = - Hyperlipidema = - Nervousness, sweating
Thyroid Gland
18
Produces: 1. T3 (tri-iodothyronine) 2. T4 (thyroxine) 3. Calcitonin - ↓ blood Ca+2
Increase body metabolism
Parathyroid Glands
Anterior View
PosteriorView
Produce: Parathyroid hormone - ↑blood Ca+2
9/7/2018
10
19
Thyroid gland disorders – Clinical App ONLINE A. Hyperthyroidism = excessive thyroid hormones Causes: - thyroid tumor - Graves disease = autoimmune attack, over-stimulates thyroid receptors. Clinical presentation: - High metabolism & anxiety - Intolerant to heat (sweating) - Tachycardia - Hypertension -↑ fluid behind eyes (“exopthalmos”)
B. Hypothyroidism = insufficient thyroid hormones
Causes: thyroid tumor, goiter, insufficient dietary iodine. Clinical presentation: - Low metabolism, depression - Intolerance to cold, dry skin, - Enlarged thyroid gland - When in children called “cretanism”
“Goiter” = thyroid can’t make thyroid hormones, it over-grows (swells)
20
9/7/2018
11
Gonads
21
Testes Ovaries
Response to LH = _____________ Response to FSH = _____________
Response to LH = _____________ & _____________ Response to FSH = _____________
A. Kallmann Syndrome (Hypogonadism) = insufficient hypothalamic GnRH production. Results in less pituitary LH & FSH. Causes ↓testes growth and ↓ testosterone and estrogen production. In male child – can interfere with development of penis, testes, sperm production, and other masculine traits.
Sex Steroid Disorders:
9/7/2018
12
B. Androgen Insensitivity Syndrome (AIS)
= in male fetus, failure of tissues to respond to testosterone. Causes feminization. Partial AIS - Micropenis or enlarged clitoris, partial or no closure of scrotum.
Complete AIS – Clitoris rather than penis, hip & breast development at puberty. No female repro structures inside. Testes retained in abdomen (must be removed!)
Partial AIS – partial fusion of scrotal skin, micropenis or enlarged clitoris
Complete AIS
24
Pineal gland
Pancreas
- Makes melatonin at night - helps regulate circadian rhythm
- Makes insulin and glucagon Clinical App ONLINE Diabetes mellitus & Physiology in Health & Disease Pg 220
9/7/2018
13
25
GI Tract 1. Gastrin (stomach) = stimulates HCL production (by parietal cells) 2. Secretin (sm. intestine) = stimulate water and bicarbonate secretion from pancreas 3. Cholecystokinin (sm. intestine) - stimulates gallbladder contraction (get bile into duodenum) - stimulates pancreatic enzyme secretion 4. Gastric inhibitory peptide (sm. intestine) = - slows gastric motility (slow down) - stimulates pancreatic insulin.
Review
• Endocrine glands of body – Pituitary, adrenals, thyroid, parathyroids, gonads, pineal gland, pancreas, GI tract
• Endocrine disorders
26